Abstract:
Part 1 is a rigorous examination of System E. Chapters I - V highlight properties of the system by (a) proving theorems and metatheorems, and (b) by comparing E with other logical systems. Chapter VI presents a partial solution of an "unsolved problem" of the system. Chapter VII critically examines the theory.
Part 2 is a survey of the literature on the subject of entailment. Recent literature, especially that relating to System E, is carefully summarized and where necessary critical comment is made. The same procedure has not been adopted for earlier writings on entailment as there has already been sufficient comment by other writers.